Question: $b(n) = -1 \left(2\right)^{n - 1}$ What is the $5^\text{th}$ term in the sequence?
Answer: This is an explicit formula. All we have to do is plug $n=5$ in the formula to find the $5^\text{th}$ term. $\begin{aligned} b({5}) &=-1(2)^{{5} - 1} \\\\ &= -16 \end{aligned}$ The $5^\text{th}$ term is $-16$.